1. Field of the Invention
The present invention relates to a display device, and more particularly, to a display device which uses micro-electro-mechanical systems (MEMS) for pixels.
2. Description of the Related Art
A micro-electro-mechanical system (MEMS) display is a display expected to replace a liquid crystal display (see Japanese Patent Application Laid-open No. 2008-197668). This display differs from a liquid crystal shutter type display utilizing polarization, and performs light-dark display by opening and closing a light transmissive window using a mechanical shutter system. Amechanical shutter (hereinafter, simply referred to as shutter) is formed of an amorphous silicon film. Vertical and horizontal sizes of one shutter forming one pixel are in the order of several hundred micrometers, and a thickness thereof is in the order of several micrometers. One shutter is opened/closed to enable ON/OFF operation for one pixel. The shutter is operated by an electrostatic attractive force.
Oil is filled inside a panel in which the shutter operates, and the oil increases the dielectric constant in the panel, to thereby reduce a voltage necessary for driving the shutter. The oil is sealed by a sealing agent, but the oil may leak due to exfoliation or damage of the sealing agent. When the oil leaks, an air bubble may be generated in the panel (region filled with the oil). However, a difference of color between the region filled with the oil and a region in which an air bubble is generated is very small, and visual inspection of the difference, namely visual inspection of presence of an air bubble is difficult.